DS1315S-33+

Overview

The DS1315S-33+ is a Phantom Time Chip combining a CMOS timekeeper and nonvolatile memory controller. It tracks hundredths of seconds, seconds, minutes, hours, day, date, month, and year with automatic leap year correction valid to 2100. Operating at +3.3V (3.0V–3.6V range), it uses serial pattern recognition for communication without address space requirements. The device supports battery backup for external SRAM via VCCO and redundant battery attachment. It features industrial temperature availability (-40°C to +85°C) and comes in a 16-pin SO package.

Feature Summary

• Phantom Clock interface using 64-bit serial pattern recognition
• Automatic leap year correction valid through 2100
• Nonvolatile controller for battery-backed SRAM/ROM
• Redundant battery support for high reliability

Applications

• Systems requiring nonvolatile timekeeping without address bus overhead
• High-reliability applications utilizing redundant battery inputs
• Embedded devices interfacing with external CMOS static RAM

Procurement Notes

Verify the specific suffix 'S-33+' confirms the 16-pin SOIC package and 3.3V operation. Confirm the operating temperature range matches system requirements; commercial grade is 0°C to +70°C while industrial grade (-40°C to +85°C) requires the 'N' suffix (DS1315SN-33+). Check RoHS compliance status as indicated by the '+' symbol.

Selection Notes

Select this component when a serial-only interface is preferred to save microcontroller pins. Ensure the external crystal has a 6pF load capacitance. For systems requiring industrial temperature performance, specify the DS1315SN-33+. Verify that the host system can generate the required 64-bit write cycle sequence for pattern recognition.

Part Context

This part belongs to the DS1315 family of Phantom Time Chips. The 'S' indicates a 16-pin Small Outline package, and '33' denotes 3.3V operation. The '+' signifies lead-free/RoHS compliance. Other variants include PDIP packages and 5V versions.

Replacement Considerations

For industrial temperature -40°C to +85°C, use DS1315SN-33+. For 5V operation, consider DS1315S-5+ or DS1315SN-5+. Package alternatives include the 16-pin PDIP (DS1315N-33+) or 20-pin TSSOP (DS1315EN-33+).

FAQ

How does the DS1315 communicate with the host?

It uses a 'Phantom Clock' interface based on pattern recognition of a 64-bit serial bit stream, eliminating the need for dedicated address lines.

What is the function of the ROM/RAM pin?

Connecting ROM/RAM to ground enables RAM mode for battery-backed SRAM control. Connecting it to VCCO enables ROM mode, disabling battery backup functions as ROM is read-only.

Does the device support leap years?

Yes, the DS1315 automatically adjusts for months with fewer than 31 days and includes leap year correction valid up to the year 2100.